治太阳风寒两伤, 营卫同病. 伤寒之脉而见中风之
证,中风之脉而见伤寒之证, 二证俱不出汗而烦躁者, 用此两解发汗
.虽有是证, 若脉微弱, 自汗出者, 不可服之, 服必亡阳.
麻黄 ( 去节 ) 六两 桂枝二两 杏仁 ( 去皮, 尖 ) 四十个 甘草
(炙 ) 二两 生姜 ( 切 ) 三两 大枣 ( 擘 ) 十二枚 石膏 ( 碎
,绵裹 ) 如鸡子大, 右七味, 以水九升, 先煮麻黄, 减二升, 去上
沫,纳诸药, 煮取三升, 去滓, 温服一升, 取微汗. 汗出多者, 温粉
扑之. 一服汗者, 停后服. 汗多亡伤, 遂虚, 恶风烦躁不得眠也.
【注】何以知风寒两伤, 营卫同病? 以伤寒之脉而见中风之证, 中风
之脉而见伤寒之证也. 名大青龙汤者, 取龙兴云雨之义也. 治风不外
乎桂枝, 治寒不外乎麻黄, 合桂枝麻黄二汤以成剂, 故为兼风寒中伤
者主之也. 二证俱无汗, 故减芍药, 不欲其收也. 二证俱烦躁, 故加
石膏以解其热也. 设无烦躁, 则又当从事于麻黄桂枝各半汤也. 仲景
于表剂中加大寒辛甘之品, 则知麻黄证之发热, 热全在表; 大青龙证
之烦躁, 兼肌里矣. 初病太阳即用石膏者, 以其辛能解肌热, 寒能清
胃火, 甘能生津液, 是预保阳明存津液之先着也. 粗工疑而畏之, 当
用不用, 必致热结阳明, 斑黄狂胃, 纷然变出矣. 观此则可知石膏乃
中风伤寒之要药, 得麻, 桂而有青龙之名, 得知草而有白虎之号也.
服后取微汗, 汗出多者, 温粉扑之. 一服得汗, 停其后服, 盖戒人即
当汗之证, 亦不可过汗也. 所以仲景桂枝汤中不用麻黄者, 是欲其不
大发汗也; 麻黄汤中用桂枝者, 恐其过汗无制也. 若不慎守其法, 汗
多亡阳, 变生诸逆, 表遂空虚而不任风, 阴盛格阳而更烦躁不得眠也
.
治疗太阳经受风寒两邪侵袭，营气和卫气同时发病。出现伤寒的脉象却伴有中风的症状，或出现中风的脉象却伴有伤寒的症状，这两种证候都表现为无汗且烦躁不安的，使用此方进行双重解表发汗。虽然具备上述证候，但如果脉象微弱、自发出汗的，不可服用本方，服用后必然导致阳气亡失。
麻黄（去节）六两 桂枝二两 杏仁（去皮、尖）四十个 甘草（炙）二两 生姜（切）三两 大枣（擘开）十二枚 石膏（打碎，用棉布包裹）如鸡蛋大小。以上七味药，用水九升，先煮麻黄，水量减少二升，撇去水面上的浮沫，加入其余药物，煎煮至取药液三升，滤去药渣，温服一升，以取得微汗为宜。如果出汗过多，用温粉扑洒身体。服用一次后若已出汗，停止服用后续药物。若因出汗过多导致阳气亡失而损伤正气，致使身体虚弱，出现怕风、烦躁、无法入睡等症状。
【注释】如何知道是风寒两伤、营卫同病呢？是因为出现了伤寒的脉象却见中风的症状，或者中风的脉象却见伤寒的症状。命名为大青龙汤，是取龙兴起云致雨的含义。治疗风邪不外乎使用桂枝，治疗寒邪不外乎使用麻黄，将桂枝汤和麻黄汤两方合并组成此剂，所以作为兼治风寒中伤的方剂。两种证候都无汗，所以减去芍药，不希望它收敛。两种证候都有烦躁，所以加入石膏来解除内热。如果没有烦躁症状，则应当采用麻黄桂枝各半汤。张仲景在解表剂中加入大寒、辛甘性质的药物，由此可知麻黄证的发热，热邪完全在体表；大青龙汤证的烦躁，热邪兼涉肌肉腠理之内。初起患太阳病就使用石膏，是因为石膏辛能解散肌热，寒能清泻胃火，甘能生津液，这是预先保护阳明经、保存津液的先手之策。庸医怀疑并畏惧石膏，该用不用，必然导致热邪结聚于阳明经，出现斑疹、发黄、狂躁、胃热等病症，各种变证纷至沓来。观察这一点就可以知道，石膏是治疗中风和伤寒的关键药物，配合麻黄、桂枝便有了“青龙”的名号，配合知母、甘草便有了“白虎”的称号。服药后要求取得微汗，如果出汗过多，用温粉扑身。服用一次得到汗出，就停止后续服用，这是告诫人们，即使是应当发汗的证候，也不可以过度发汗。之所以张仲景在桂枝汤中不使用麻黄，是希望不要大发其汗；在麻黄汤中使用桂枝，是担心发汗过多而失去节制。如果不谨慎遵守这些法则，导致出汗过多而亡阳，产生各种逆证，表气随即空虚而不能抵御风邪，阴寒内盛格拒阳气于外，反而更加烦躁、无法入睡。
Treats the condition where both Wind and Cold pathogens invade the Taiyang (Greater Yang) channel, causing simultaneous disorders of Ying (Nutritive Qi) and Wei (Defensive Qi). When the pulse characteristic of Shanghan (Cold Damage) presents with symptoms of Fengzhong (Wind Strike), or the pulse characteristic of Fengzhong presents with symptoms of Shanghan, and both conditions manifest as anhidrosis (absence of sweating) accompanied by restlessness (Fan Zao), this formula is used to resolve both exterior constraints through diaphoresis. Although these signs are present, if the pulse is faint and weak (Mai Wei Ruo) with spontaneous sweating (Zi Han Chu), this formula must not be administered; doing so will inevitably lead to the loss of Yang Qi (Wang Yang).
Mahuang (Ephedrae Herba, stems removed) liang (approx. 30g in modern context, but keep original unit: 6 liang)
Guizhi (Cinnamomi Ramulus, 2 liang)
Xingren (Prunus Semen, skin and tips removed, 40 units)
Gancao (Glycyrrhizae Radix et Rhizoma, honey-fried, 2 liang)
Shengjiang (Zingiberis Rhizoma Recens, sliced, 3 liang)
Dazao (Ziziphi Jujubae Fructus, broken open, 12 pieces)
Shigao (Gypsum Fibrosum, crushed, wrapped in cotton cloth, size of a chicken egg)
The above seven ingredients are decocted in nine sheng (approx. 1800ml) of water. First, boil Mahuang until the volume reduces by two sheng; remove the foam from the surface. Then add the remaining herbs and continue boiling until three sheng of liquid remain. Strain the dregs. Take one sheng warm. The goal is to induce slight sweating. If sweating is excessive, apply Wen Fen (warm powder) to the body. If sweating occurs after the first dose, discontinue subsequent doses. Excessive sweating leading to Yang loss causes injury and deficiency, resulting in aversion to wind (E Feng), restlessness, and inability to sleep.
[Note] How do we know it is a dual invasion of Wind and Cold affecting both Ying and Wei? It is identified by the presence of Shanghan pulses with Fengzhong symptoms, or Fengzhong pulses with Shanghan symptoms. The name Da Qing Long Tang (Great Azure Dragon Decoction) derives from the imagery of the dragon raising clouds and rain. Treating Wind pathogen relies primarily on Guizhi; treating Cold pathogen relies primarily on Mahuang. By combining Guizhi Tang and Ma Huang Tang into one prescription, it serves as the primary formula for concurrent Wind-Cold invasion. Since both conditions involve anhidrosis, Shaoyao (Paeoniae Radix Alba) is omitted to avoid its astringent properties. Since both conditions involve restlessness, Shigao is added to clear heat. If restlessness were absent, one should instead use Ma Huang Gui Zhi Ge Ban Tang (Half-Ma Huang Half-Guizhi Decoction). Zhang Zhongjing’s inclusion of cold-natured, acrid-sweet herbs in exterior-resolving formulas indicates that in Mahuang syndrome, fever is entirely at the exterior level; whereas in Da Qing Long Tang syndrome, restlessness implies heat has penetrated deeper into the muscle layer. Using Shigao early in Taiyang disease utilizes its acrid nature to release muscle heat, its cold nature to clear Stomach fire, and its sweet nature to generate fluids, thereby preserving Yin fluids and protecting the Yangming (Stomach/Large Intestine) channel preemptively. Incompetent physicians may doubt and fear Shigao, failing to use it when necessary, which inevitably leads to heat binding in Yangming, presenting with macules, jaundice, mania, and gastric heat, causing various complications. Observing this reveals that Shigao is a crucial herb for both Wind and Cold diseases; combined with Mahuang and Guizhi, it earns the name "Qing Long" (Azure Dragon); combined with Zhimu and Gancao, it forms the basis of "Bai Hu" (White Tiger) formulas. After administration, slight sweating is desired. If sweating is excessive, apply warm powder. If sweating occurs after one dose, stop further doses. This warns that even in cases requiring diaphoresis, one must not sweat excessively. Zhang Zhongjing omits Mahuang from Guizhi Tang to prevent excessive sweating; he includes Guizhi in Ma Huang Tang to prevent uncontrolled sweating. If these methods are not carefully observed, excessive sweating leads to Yang loss and various adverse transformations. The exterior becomes deficient and unable to resist Wind; Yin excess repels Yang, leading to intensified restlessness and insomnia.